Broad beam x-ray sources, such as shown in FIG. 1 at reference character 10, are commonly known, and typically utilize a scanning technique of a highly collimated electron beam to develop a line or raster scanned pattern. In particular, these broad beam X-ray sources include a hot filament cathode 11 to produce electrons, and a positively-charged anode 16, i.e. an x-ray conversion target such as tungsten, spaced from the cathode to draw and accelerate the electrons to a specified energy. Between the anode and cathode are focusing and auxiliary electrodes 12 to focus the electrons into an electron beam 14, and deflection plates 13, e.g. electrostatic or magnetic deflection plates, to scan the electron beam 14 across the X-ray conversion target 16 as indicated by arrow 15 and generate x-rays from the various scanned locations/points of the target. The x-rays generated in this manner can be directed at a subject 17, e.g. a patient or object, and detected with a suitable detector 18 for imaging the subject. One example of such an x-ray imaging system using electron beam scanning is shown in U.S. Pat. No. 6,628,745. Other methods may use mechanical means to move the x-ray source relative to a detector and object so as to also generate x-rays from spatially-differentiated locations. In any case, such methods are often used, for example, in CT scans of luggage, cargo containers and the like for security and commercial inspection purposes, as well as for use in medical diagnostic applications.
The problem, however, with the scanning technique utilized in current broad-beam x-ray sources is the large and bulky size typically associated with such systems due to the geometry of the scanning arrangement. Scanning over a large area x-ray conversion target requires that the electron beam undergo a drift (i.e. separation distance between cathode and anode) comparable to the longest dimension of the area to be scanned in order to reach the outer extremities of the target. Due to this geometric limitation, the dimensions of the vacuum envelope of the x-ray source (spanning between the hot filament to target) consumes a significant portion of the overall system size, making the system large, cumbersome, and usually very expensive. Because designers cannot easily anticipate the wide variety of objects a user would seek to image, and the expense of such large-scale/dimensioned systems is so significant, a “one size fits all” mentality is incorporated into the design and acquisition of very large aperture x-ray imaging systems, with the net result being a narrowed use of the technology only by larger institutions.
What is needed therefore is a compact, scalable, and relatively inexpensive x-ray source that can be used in a broad range of settings and for imaging a wide variety of target subjects/shapes. Furthermore, what is needed is a compact x-ray source panel having a simple basic construction which is scalable and enables complex panel shapes to be realized for adaptably conforming to a subject to be imaged. Such an x-ray source and imaging system would be particularly useful, for example, in emergency medical response situations by targeting and imaging only specific areas, e.g. a patient's traumatized head, to provide rapid diagnosis of the injury and implement the appropriate emergency procedure.